This invention relates to systems for moving people and freight, such as elevators, in which wireless electromagnetic transmissions are used to communicate between the fixtures at each stop (such as hall fixtures of an elevator) and a controller, in order to respond to and inform passengers of the stops, and in particular, to a two-part wireless system that uses a low power system to communicate between hall fixtures and a high power system to communicate to and from a group or system controller.
A conventional elevator system group has a xe2x80x9criserxe2x80x9d which includes, for each floor, at least one up hall call request button with an associated light to indicate that the group controller has registered the request (except for the highest floor), at least one down hall call request button with an associated light to indicate that the group controller has registered the request (except for the lowest floor), and at least one gong for providing an audible indication that a cab is about to arrive. In addition, on each floor, each elevator hatchway has associated with it a set of lanterns that identify which of the elevators is about to arrive, and depending on which of the lanterns is lit, the direction in which the elevator is currently traveling. The highest and lowest floors have only one lantern in a set of lanterns, whereas the remaining floors have two lanterns per set. In addition, cab position indicators are provided for each elevator in the group on major floors such as lobby floors, which indicate the current floor position of the corresponding elevator cab. Herein, floor position is taken to be equivalent to the committable floor of the cab (that is, the next floor where the cab could possibly stop, or a floor where it is stopped).
Regardless of how many individual processors are utilized, multi-elevator groups employ a car controller for each car, with a group controller for the entire group, or a distributed controller which provides both car and group functions. Each car controller communicates with the corresponding elevator car by means of a traveling cable, and the various car controllers communicate with the group controller over cables. In turn, the group controller communicates over wires with the hall fixtures previously described.
In large systems, such as several groups each having 15-25 floors, the amount of wire involved in enormous. Whenever upgrading is to be achieved, modifications to the elevator wiring (which is embedded in the building) can be extremely difficult, if not sufficiently prohibitive so as to confine the nature of the upgrade to that which will conform to the wiring. When upgrades or new elevator systems are to be provided in occupied buildings, the time required to rewire or reconfigure the wiring of a building can be prohibitive due to the need to have minimal intrusive shutdown of elevators during the work, so that use of portions of the elevator system by paying tenants can continue throughout the work period.
Similar equipment with similar problems may be found in horizontal transport systems as well as in systems that provide both vertical and horizontal transportation.
Direct point to point communications have been proposed to overcome problems associated with communicating between fixtures in elevator hallways and the centralized controller. This potential solution has the problem of requiring each fixture to have a relatively powerful transmitter with concomitant complexity, leading to cost increases and increases in power usage.
Briefly stated, elevator system hall fixtures such as lanterns, hall call button switches and lights, gongs, and floor position indicators are connected to a controller via wireless transceivers. The controller can be a system, group, and/or car controller. A low power wireless system connects all fixtures on one hallway, with a higher power wireless system connecting each hallway with the appropriate controller.
Elevator systems, whether horizontal, vertical, or inclined, transmit and receive control signals via a wired network using a time division multiple access (TDMA) protocol. The time and expense incurred while installing the wired network can be reduced by using wireless communication methods between floor hall call fixtures, lanterns, and floor position indicators. The wireless fixture also reduces the amount of time personnel have to work inside the hoistway, an inherently dangerous environment. A low power, unlicensed spread spectrum communication system according to the invention has been demonstrated to perform all control functions for an elevator hoistway system including hall calls and lantern indications using point to point RF communications. The point to point communication system overcomes large scale and small scale fading effects on propagation within the elevator hoistway at ranges up to 150 meters.
According to an embodiment of the invention, an elevator system in a building having a plurality of hoistways, each hoistway having an elevator cab moving therein to provide service to a plurality of floors in the building, includes a plurality of hall fixtures at each floor including at least one service call request button switch for requesting service along the hoistways in a corresponding direction, and a service call request button light for each of the service call request button switches; connection means for connecting each of the hall fixtures on each floor to a high power electromagnetic floor transceiver located on the same floor in close proximity thereto; a controller having a high power electromagnetic controller transceiver operatively associated with each of the floor transceivers for exchanging electromagnetic messages between each floor and the controller; and the floor transceivers transmitting to the controller transceiver messages indicating the activation of one of the service call request buttons, the controller transceiver transmitting messages to selected ones of the floor transceivers to cause a service call request button light to be turned on in response to registering a corresponding service call request for that floor and to be turned off in response to one of the elevator cabs approaching the related floor to provide service.